A method of fabricating a semiconductor plastic package can include: providing a core board, which includes at least one pad, and which has a coefficient of thermal expansion of 9 ppm/° C. or lower; stacking a build-up insulation layer over the core board; forming an opening by removing a portion of the build-up insulation layer such that the pad is exposed to the exterior; and placing a semiconductor chip in the opening and electrically connecting the semiconductor chip with the pad. This method can be utilized to provide higher reliability in the connection between the semiconductor chip and the circuit board.